Hearing devices generally comprise an input transducer, such as a microphone, a power source, electric circuitry and an output transducer, such as a loudspeaker. For certain acoustical environments a microphone to record direct sound may be insufficient to generate a suitable hearing experience for a hearing-device user, e.g., in a highly reverberant room like a church, a lecture hall, a concert hall or the like. Therefore hearing devices may include a wireless receiver for wirelessly receiving sound information, e.g., a telecoil or a wireless data receiver, such as a Bluetooth receiver, an infrared receiver, or the like. When using a telecoil or other wireless technology the undistorted target sound, e.g., a priest's voice in a church or a lecturer's voice in a lecture hall, is available directly in the hearing aid by wireless sound transmission. Unfortunately, directional cues will be absent and thus, the priest's voice sounds as if it was centred in the hearing-device user's head. Furthermore, since in this situation the hearing-device microphones are typically muted, the hearing-device user may also miss out on sounds from the nearby environment, e.g., the voice of a spouse or voices of other students sitting next to the hearing-device user (assuming that the voice levels are below the un-aided hearing threshold of the user). Even though the wireless technology thus allows a hearing-device user to understand the priest or the lecturer, the auditory experience is synthetic, lacks directional and room-related cues and does not at all resemble the normal hearing experience in a church, a lecture hall, a concert hall or the like.
US 2003/0223592 A1 discloses a microphone assembly comprising a transducer, a pre-amplifier, controllable switching means and an analog-to-digital (ND) converter. The transducer receives acoustic waves through a sound inlet port and converts the received acoustic waves to analog audio signals. The pre-amplifier has an input and an output terminal. The input terminal is connected to the transducer to receive analog signals from the transducer. The switching means have one or more input terminals, of which one or more terminals are connected to the output terminal of the pre-amplifier to receive amplified analog audio signals from the pre-amplifier. The analog-to-digital converter has an input and an input/output terminal, with the input terminal being connected to the output terminal of the switching means to convert received analog audio signals to digital audio signals. The microphone assembly may be connected to a telecoil unit. The switching means is adapted to select if either an analog signal from the microphone or if a signal from the telecoil unit is connected to the A/D converter to be converted to a digital signal.
EP 1 443 803 A2 discloses a hearing device comprising at least two analog input signal sources, at least one analog-to-digital converter, further processing means, input signal routing means, and signal detection means. The analog-to-digital converter generates a digital input signal from an analog input signal. The processing means digitally process the input signals. The input signal routing means selectively route each one of one or more selected input signals to the further processing means. The signal detection means are configured to analyse the analog input signals and to control the signal routing means according to results of the analysis.
In DE 43 27 901 C1 a device for supporting the hearing is disclosed with two microphones, each of them included in an ear housing and coupled to a control unit, and with at least one transmission unit. Each of the ear housings is adapted to be mounted in an area of a human ear and includes a transmitter, which is adapted to communicate with a receiver in the area of the control unit. The control unit is separated in space from the two microphones. The control unit receives input signals from the microphones. A comparison unit for evaluation of the input signals of the microphones is arranged in proximity to the control unit. The comparison unit modifies the output power of the control unit for a three dimensional sound replay. The control unit transmits at least one output signal to the at least one transmission unit. At least one transmission unit is arranged in the area of one of the ear housings. The comparison unit may comprise a time correlator.
WO 2011/027004 A2 discloses a method for operating a hearing device that is capable of receiving a plurality of input signals. A first step of the method is to extract source identification information embedded in the input signals. The source identification information identifies a signal source from which the input signal originates. A second step of the method is to extract audio type information embedded in the input signals. The audio type information provides an indication of the type of audio content present in the input signal. A third step of the method is to select input signals from the plurality of input signals for processing. The step of selecting is at least partly dependent on the extracted source identification information and/or the extracted audio type information. A fourth step is the processing of the selected signals. The step of processing is at least partly dependent on the extracted source identification information and/or the extracted audio type information. A fifth step is to generate an output signal of the hearing device by the processing of the selected signals. The method may comprise a step of processing in which a weighted sum of one or more modified signals is formed with the weighting being at least partly dependent on at least one of the extracted source identification information, the extracted audio type information and a sound class. A hearing device comprising means to perform the method is also disclosed.
EP 2 182 741 A1 discloses a hearing device with a microphone unit, a receiver unit, a classification unit and a signal processing unit. The microphone unit is adapted to record a sound signal and the receiver unit is adapted to record an electric or electromagnetic signal. The classification unit is adapted to determine an acoustic situation from the signals recorded by the microphone unit and the receiver unit. The signal processing unit is adapted to process the signals of the microphone unit and the receiver unit in dependence of an output signal of the classification unit. A time delay for an audio signal may be preconfigured in the signal processing unit.
DE 101 46 886 A1 discloses a hearing device with an acoustic signal input, an induction signal input, a control unit and a comparison unit. The acoustic signal input is adapted to receive an acoustic signal and the induction signal input is adapted to receive an induction signal. The comparison unit is adapted for comparing the received acoustic signal with the received induction signal and to deliver a comparison result to the control unit. The control unit is adapted to control the hearing device in dependence of the comparison result. In a method to control the hearing device a control step may comprise the decision of the acoustic signal and/or the induction signal to be the input signal for the hearing device. The acoustic signal and the induction signal may be mixed in the hearing device.